1. Field of the Invention
The present invention relates to a scan type anamorphic magnifying apparatus mounted in a copying machine or the like for scanning an original document and enlarging or reducing copies of the document to a selected size with different rates of change for longitudinal and transverse dimensions.
2. Description of the Prior Art
A known scan type anamorphic magnifying apparatus comprises a scanning device for causing a slit to scan an original document transversely thereof, and an image forming device for projecting and forming an image of the document on a photosensitive member moving in a direction corresponding to the direction in which the slit scans the document. The image is formed in different magnifications in the scanning direction and a direction perpendicular thereto by differentiating a speed of scanning by the scanning device and a speed of movement of the photosensitive member. With this type of apparatus, however, the image projected on the photosensitive member becomes blurred and has a reduced resolving power because the speed of scanning the document and the speed of movement of the photosensitive member are different in the direction corresponding to the scanning direction.
An apparatus has been proposed in which a cylindrical lens is fixedly provided on a projection optical path leading to the photosensitive member in order to prevent the reduction of resolving power. However, this apparatus as well as the other have the drawback of a limited magnifying power range for realizing permissible resolving power.